Doorlatch



Patented Feb.11',10a6 I 2,030,030.

` UNITED- n STATES PATENT OFFICE I William A. Gram, Wainileet Township, y Welland County, Ontario, Canada Application May 0, `1935,1seria1 No. 20,000

" 10 claims; (c1. 292-210) My invention relatesto improvements in door* into a door 2` adjacent'a jamb 3 havinga stop 4 latches, and an object of my invention is to de#l on' which is secureda slotted keeper plate 5 vise a latch, particularly adapted for use on acrossjthe free ends of which alatch keeper 6 the doors of motor vehicles and aircraft, having j is secured. I I

a substantially hook-'shaped latch element A substantially cylindrical latch element 1 ro- 5 adapted to surround a keeper elementen the door tatably positioned on a pin `8 secured in the latch 'jamblso that `accidental opening of thedoor due .casingl has a latch keeper engaging notch 9 in f to vibration is impossible.` I its periphery randa stoppin "I0 projecting from Another Object iS t0 provide a latch which will one face. The latch element is actuated by a 10 permit the door to be held shut securely even rod fll` pivotally secured at one end by a pin I2 10 when it is prevented from eemple'telyabutting in a recess in the periphery ofthelatch element the jamb, such as by warping of the door or by at a point approximately diametrically opposite the PFeSenee ofA obstructions between 4the door the notch 9,'the opposite end of the rod I I passing I 4 and lamb. freely through an orice I3 in the latch casing 0 A still further object is to devise a latchwhich Y and terminatngin a piston I4, adapted to recip- 15 Will be Particularly rugged and which it will be` recate inl 'a dash-pot cylinder' I5 and carrying substantially impossible, to force vapart when a sealing washer I6. A spring I1 around the rod locked. II` is compressed' between a stop I8 on the rod Yet another object ls to provide a latch having` andone endvof the latch casing I.

zo pneumatic meansfor ensuring gentle closing of The latch element l is heldin the door latching `20 Ithe door and preventing slamming. I fpositionwbya rod I9 pivotally `connected `atone` An additional object is to provide means Aforl end to the 'stop I8`on the rod Il and having locking my latch inthe door letchng position a toothed dog'zmon its; free endg/nich is adaptedV by `freeing the latch mechanism from `the'latch to engage a toothed rack 2| secuedto thelatch 25, Operating means 'so that the latch cannot be j casingl. A spring I9' serves tourge the free .25

forced by attacking such means. n end of the rod I8`against `the rack'2 y Yet another object `isf-to devise a latch includ v A latch operating shaft 22 is journalled in an ing means whereby operation of the latch operatorifice inthe casing I being secured therein by ing means willopelfl the door through the latchthe shoulders" 23, and has an `operating handle ing position without any pull on the door 'being 24 thereon. Such shaft projects into the bore of 30 required. a hollow shaft 25 which 'alsopasses through an With `mese and Other Objects in viewpwl'iich` oriilcein the latch casing I and terminates in Will hereinafter Lappear aS the Speeieetion Proa secondoperating handle 26, A sleeve 21 around Y ceeds my invention consists, in its preferredemthe `shaft 'i2` carries a latch releasing member bodiment, ofthe construction andr arrangementv 2a adapted to engagethe rod I9 along the edge 35 all es hereinafter mOIe particularly described 29 ofthe member, such member 28 being conandillustrtd with reference to the accompany# netted bya came 30 to the stop 'la onine rod ing drawing, in which: a, springml connected at one extremity to a pro- Figl 1 is a fragmentary elevationalV view of a `jeetivqn 32 on the` `:menubar-"280 and at the vother 40, door, and .doofe-lamb Showing my latch installed' to one end ofthe latch casing'I serving to normal- 40 t thereon and with part of the latch casing broken 1y' hold the member 20 againsta Stop 33 on the away to reveal thelatch mechanism; cs'ing Fig' 2 15,8' longtudmal Secmqnal View'thereof l'Operative connection between the `handles 24 taken along the hne of Flg. 1, Showing in 2s` and latch releasing member is ef broken lines the positions `the latch elements I I i `4.5 assume when the door is open; I Y I, i fectedby means of bosses 34 proJecting from a Fig. 3 ls a transverse sectional view taken along:` a'nge '35 on theshaft 22 which are adapted toi the une 3 4 of Fig 2; and i enter correspondingly shapedrecesses 36 and 31 I Fig. 4 is a' fragmentary elevational View fthe in integral flanges 38 andI ."Iliv on the hollow shaft doorjambl showing the latch keeper installed 25 end l211e Sleeve 2l respectively, .a spring 40 50 thereon, I around the-shaft 25 compressed between the cas-` Like characters of reference refer to corres; ing I and the flange 38 and a. second spring 4I pending parts in the'diiferent views. around the shaft 22 compressed between the I Referring to thedrawlng, my improved latch casing 1I and the sleeve '2l serving to hold the mechanism may be contained in a casing I set flanges 38 ar`1d `39`in engagement with the ange 55 35. An orthodox cylinder lock 42 having a rotatable shaft 43 carrying a disc 44, the plane faces of which are at an angle to each other, is so positioned in the door 2 adjacent the shaft 22 that the periphery of the disc 44 projects between the anges 38 and 39.

The operation of my latch is as follows: When the door is latched as shown in the full line positions of Figs. 1 to 3, the notch!! of thelatch element 'I engages the keeper 6, the former being held securely against rotation bythe toothed dog 20 engaging the rack 2|.

To release the latch for opening the door, either of the handles 24 and 26 are rotated in the direction to move the element 28 away from the stop 33 which it normally abuts. The rst slight rotation of the element 28 permitted by the slack in the cab-1e 3U lifts the dog 20 out of engagement with the rack 2|, allowing movement of the rod I-I. Further rotation of the element 28 then takes up the remaining slack in the cable 20 and pulls the rod I I in a direction to further compress the spring I'I and rotate the latch element, such rotation causing one side ofthe notch 9 to bear against the outer surface of the keeper 6 to open the door slightly. When further rotation of the element I causes the pin I2 to cross a line joining .the pin 8 and the centre of the orice I3, the spring causes the element 'I to rotate by a snap action until the stop pin Ill abuts the latch casing I,

imparting aV further opening impulse to the door.`

With the latch mechanism in this position (indicated by the dotted lines in Fig. 2) the notch 9 `to hold the rod I I and connected latch element .1

against movement.

To latch the door either oi the handles 24 and 26 are rotated sufciently to free the dog from the rack, and the door is swung shut. After the keeper 6 `enters the notch 9, further movement of the door towards the jamb revolves the latch element "I until the pin I2 recrosses the line between the pin and the orice I3,.whereafter the spring Il causes the element I to rotate further, by a snap action, to force the door tightly against the jamb. It shouldbenoted that o-nce the pin I2 has crossed the line joining the pin 8 and the orifice I3, the spring I'I acts to keep the latch element 'I in engagement with the keeper 6, and the 4dog 20 engaging the rack 2| prevents reverse motion ofthe element I which wouldfree the door for opening. During this final movement of the element I, the piston I4, moving out of the cylinder I5 against the atmospheric pressure, retards the move-ment of the rod II and the element 1 to` prevent slamming of the door, but without decreasing the closing force exerted' by the spring I1.

To lock the latch, the lock 42 is actuated by its key, which causes the shaft 43 carrying the disc 44 to rotate from the normal unlocked position with the thin edge of the disc between the flanges 38 and 39, until the thick edge is between the `flanges, thus forcing the flanges apart against the tension of thesprings 4G and 4I, until the bosses 34 on the iiange 35 no longer engage the recesses 36 and 3l inthe flanges 38` and 39 respectively. The handles24 and 26 are then free to revolve without operating the latch. On unlocking the latch, it is only necessary torevolve either handle until a boss 34 enters th'corresponding recess, when operative connection between the handle and the latch releasing member 28 is reestablished.

An advantage of my improved latch is that since the latch element 1 substantially surrounds the keeper E, the door islatched very securely, and the forcing of thedoor by means of an instrument inserted betweenl the door and the jamb is precluded. l y l A further advantage is that the latching and unlatching of the dooris positively effected by the snap action of the spring I3, so that any dimculty in closing and opening the door due to binding of the latter against the jamb is eliminated. L

Yet another advantage of my construction is that it provides, bymeans of the dog mechanism, for positive latching of the door even if the latter is not tightlyclosed, and in addition the position of most complete closing reached is always maintainedV since the dog follows the closing motion` of the latch but never permits reversal of such.

motion until released by the operating handle. An additional advantage fof my latch is that the pneumatic piston and cylinder ensures smooth and substantially noiseless latching of the door.

While I have described and illustrated one preferred form of, my invention, it will be obvious that there are numerous other ways of embodying the principles of my device, so my disclosure is intended to impose no limitation on the scope of my invention beyond that set, forth in the apy pended claims.

What I claim as my invention is:

1. A door latch, adapted to latch on a keeper pin positioned on the door jamb, comprising a rotatable latch element journalled in the door adjal cent the edge thereof kand having a radial slot adapted to receive, the keeper pin during rotation of the latch elementinto the latching position as thedoor is closed, vspring means for actuating the latch element alternativelvinto thedoor latching and .the door opening positions, and re.-

leasable means for retaining the latch element in the position of greatest rotation attained dur-x ing the latching of the door.

2. A door latch as claimed in claim 1 wherein means is provided for manually actuating the latch element against the action of the spring means from the door latching position to the position where the spring means acts to actuate the latch element into the doorv opening posi-` tion.

3. A door latch as claimed invclaim 1 wherein.

means is provided .for manually actuating the latch lelement against the action of the spring means from the door latching position to the position Where the spring means acts to actuate the latch element into the door opening position and means for locking the latch when in the door latching position comprising a releasable operative connection between the manual actuating means and the latch element.

4. A door latch as claimed in claim 1 whereinl otally secured at one extremityto the periphery 0f the latch element at a point'substanti'ally dipositioned that the point of connection of the ametrically opposite the slottherein, a bracket secured in the door and having an orifice therein adapted to freely receive the other extremity of said rod, a stop on said rod adjacent its pivotal `connection with the latch element, a coil spring around said rod and compressed between said stop and said bracket, the bracket being so rod' with the latch element crosses a line join` ing the centre of the latchelement and theA centre of the orifice in the bracketv as the latch element rotates between the door openingand the door latching positions,fmanually operablel means for actuating- 4the latch element against the action of the springout oi' the door latching position, and means, releasableby the manually operable means, for retaining the latch element in the position of greatest rotation attained du ing the latching of the door.

6. A door latch as claimed in claim 5` `wheref tioned rod, teeth on the other extremity of said last mentioned rod adapted to engage the teeth in the rack, spring means for urging the toothed rod extremity into engagementwith` the rack,`

said cam being adapted to liftthe toothed extremity of the rod out of engagement with the rack upon the initial actuation of `the manually operable means during the unlatching ofthe door, means for limiting the movement of the cam between the door opening and door latching positions, and spring means for normally retaining the cam `in the door latching position.

7.` A door latch as claimed `in claim 5 wherein` said rod, and an A y a a 3 means is provided for damping the springaction of the latch mechanism comprising a cylinder securedto the Vbracket in the door in which the free end oi the latch element actuating rod is adapt-,f`

` ed to reciprocate, a piston on thev free end of obturating member on the piston.` t i 8, Adoor ,latch` as claimed in claim 5 wherein means is provided for locking the latch "element when in the 'door latching position comprising a releasable operative connection between the manualactuating meansand the latchelement.' 9. A latchmechanism asclaimedfin claim 10 wherein said wedge means comprisesa member rotatablypositioned. adjacent said operating shaft,rand a disc carried by said member having planeV faces` disposed at .an angle to each other, said disc` being adapted` to be alternative` ly positioned with a portion of the4 periphery of v lesserthickness between said flanges for `actuation ofthe camby the operating shaft, and with a. portionof the periphery of greater thicknessbef` tween said flanges for separation of the latter to free the cam from-operative connection with i theoperating shaft for locking of the latchmechanism.

10. In a latch mechanismA including a latch op-` erating cam and a rotatable operating shaft therefor, locking means comprising a ange on the operating shaft, a boss on said flange, asleeve to which the operatlngcam is securedfsurrounding a portion of said shaft, a ilange on said sleeve` adjacent the `flange on the operating shaft and having a recess adapted to receive the boss on $5 mally urge `said anges together for engagement the` shaft flange, spring means adaptedfto nor-l of the boss in the recess for operatively connect--` ing the operating shaft with the cam, landwedge means forseparating said anges to free the cani from operative connection with the operating shaft` for locking of the ,latch mechanism.

ywILnIAllltill,Galant."` 

